An international player in the highly competitive aeronautics, automotive, defense and optical industries makes the most of software for multitasking program verification and optimization.

Editor's Commentary

The video included with this article shows the synchronization of the left and right spindles on the Nakamura-Tome WT-150 II from Methods Machine Tools. A spindle with a 0.040 x 0.040 x 3/8 link is between two spindles The spindle goes forward up to 5,000 rpm and reverse back to stop. The 0.040 x 0.040 link is still intact, demonstrating the accuracy of real spindle sync.

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This video shows the synchronization of the left and right spindles on the Nakamura-Tome WT-150 II from Methods Machine Tools. A spindle with a 0.040 x 0.040 x 3/8 link is between two spindles The spindle goes forward up to 5,000 rpm and reverse back to stop. The 0.040 x 0.040 link is still intact, demonstrating the accuracy of real spindle sync.

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CAMplete TurnMill virtually removes the part prove-outs while significantly increasing production at APN.

Today more than ever, it is crucial that North American manufacturers constantly improve on their technology and processes. Multitasking machine tools are becoming more widely used to help manufacturers compete globally. These machines introduce new challenges for ensuring that a safe and optimum NC program is obtained the first time to reduce machine downtime and program prove-out.

APN Inc., while a 42-year-old company, is an ultra-modern machine shop located in Quebec City, Quebec, Canada. Making extensive use of multitasking machine tools, the company produces parts for the aeronautic, optical, ammunition and automotive industries in a volume close to 50,000 per year.

Machines and Parts Defined

APN uses three Nakamura-Tome WT-150 multitasking machines to produce most of its high precision turned parts in batch sizes ranging from 20 parts to more than 1,000. Multitasking machines have been engineered to produce highly complex turned parts (most with complex milling features) with high accuracy and quality. Precision and high quality is an essential component of APN’s deliverables to its customers. The WT-150 consists of two spindles and two turrets that can operate independently or in a synchronized fashion. All six sides of a part can be machined and finished with a single setup, allowing production batches to be run as part of a “lights out” manufacturing environment. Parallel operation allows multiple functions to be performed simultaneously on the parts, saving significant time.

In traditional multitasking, careful optimization by experienced programmers and operators is required to effectively take advantage of the machine’s capabilities. This means long setup times on the machine and extensive part prove-outs. During this time, no parts are produced and the machine is not “making money.” There is always a trade-off between the amount of time spent on optimization (therefore increasing machine downtime during this process) and the time that the optimization saves per part.

Previous Turn-Mill Applications

In producing a certain automotive component, APN used its previous CAM software to easily recognize and program features coming from the solid model of the part. After programming was complete, though, operators would bring the non-optimized programs to the machine. From there, a long prove-out process would occur.

The operator would first check for any over-travels or potential collisions, then slowly look at which operations could be run simultaneously, manually inserting wait marks to synchronize these operations. APN also struggled with the inability to program part transfers between the main and subspindle, as well as the cutoff operation from the barstock. Depending on the number of tools and operations, this process would be lengthy, tying up the machine.

Improving Results

With large volumes of parts to produce, APN needed a solution to get the most out of its machines, rather than having them tied up doing part prove-outs. The company now uses CAMplete Solutions’ TurnMill. This integrated software solution intelligently post processes, simulates and optimizes programs exclusively for Nakamura-Tome machines. NC programmers at APN use the code generated by the CAM software, and then import it into CAMplete TurnMill to accurately simulate and optimize the programs before anything is run on the machine. The software allows APN to visualize and verify the entire setup (spindles, turrets, tools, holders) off line to avoid downtime on the machine. The biggest advantage for APN is not only the ability to optimize all the machining sequences between the main and subspindle and balance load between upper and lower turrets, but also the ability to move operations between channels and intelligently insert the proper synchronization codes where required. APN also now can adjust the part transfer and cutoff parameters.

The same part setup that used to take APN hours is now done within less than 30 minutes, off-line, while the machine is running, still producing parts from the previous job. This is a significant gain for APN and the programmers. They can now focus on optimizing the programs as much as possible without having to worry about a collision, over-travel or a tool that is set up incorrectly.

CAMplete TurnMill integrates all the aspects of the Nakamura-Tome machines. As such, APN also uses the software to get accurate time estimates and confirm the sales target established. Having the ability to accurately validate a cycle time, even before the machine is turned on, gives the company the strategic advantage its needs to take its business to the next level, beating its competitors while reducing costs.

Multitasking Feature Upgrade

Methods Machine Tools Inc. now offers the Nakamura-Tome WT-150 II eight-axis multitasking turning center, which features a number of upgrades from the base WT-150 design. With opposed twin-spindle, two-turret construction, it offers high speed and high rigidity in a compact machine.

The 19-inch high resolution, touchscreen LCD panel contributes to ease of operation, and a Fanuc 31i-B CNC and a PC-based control (NT-IPS) offer faster processing, as well as several features for increased efficiency and maintainability. Standard functions include a spindle speed override switch, a program number search, C-axis synchronization and helical interpolation (for Y-axis models).

The distance between the spindles on the WT-150 II has been increased to 31.5 inches (800 mm) while still providing the same compact machine footprint of 67.8 ft. × 67.8 ft. × 6.2 ft. (6.3 m × 6.3 m × 1.9 m). With a maximum tool swing of 23 inches (570 mm) on the upper and lower turrets, users can drill through a 2-inch (51-mm) bar diameter from one side.

With simultaneous 4+4 axis control, the WT-150 II offers eight-axis machining capability. The system includes 12-station upper and lower turrets with a half-index capability, to hold a total of 48 tools for multiple processes. A left and right spindle with speeds as high as 5,000 rpm at 20/15 hp, and a 6-inch (150-mm) chuck and 2-inch (51-mm) bar capacity are provided. The WT-150 II is capable of 7.5 hp milling capacity on the C axis.

As with all Nakamura-Tome multitasking turning centers, the CAMplete integrated Turn-Mill software suite is standard, providing G-code editing, optimization, analysis and verification tools that enable a range of turn-mill functions.

Turn-Mill Optimization

CAMplete TurnMill is an integrated software solution that intelligently post processes, simulates and optimizes programs exclusively for Nakamura-Tome multitasking machines sold by Methods Machine Tools Inc. NC programmers use the software to generate proven NC programs using input from their CAM system. The software even allows the reuse of NC code from other machines. After the NC code is generated, CAMplete TurnMill accurately simulates and optimizes the programs before they are run on the machine.

A simulation platform is only as good as the level of detail offered. All the specific G & M codes required by each Nakamura-Tome machine are supported, including advanced features such as tool center point control for five-axis machining, part transfer between spindles and synchronization codes between turrets. All machine models use the exact manufacturing CAD data directly from Nakamura-Tome’s engineering offices, eliminating the approximations and guesses of using a model obtained or designed by a third party. CAMplete TurnMill does not limit itself to the basics. Every aspect of the machine is entirely controlled, monitored and simulated as closely as possible. Even the entire tool change sequence is fully simulated and displayed on the virtual controller.

Managing Resources

Just getting a proven and collision-free program is still not enough to get the most out of the investment in a multitasking machine. With so many different elements moving and the machines’ increasing ability to handle complex parts (with features such as 2 or 3 turrets or a milling spindle mounted on a rotary axis), efficiently managing every aspect of the machine is important. Setup of the machine is best done by experienced operators because of the number of tools that need to be allocated to multiple turrets.

The software provides the ability to quickly change the fixture, re-position and re-orient parts on the fly or try a newly purchased tool. It offers a number of features to automate the tool assignment to the proper turret, automatically calculate the proper offsets and seamlessly reorganize the program or setup by copying or moving tools or entire operations. An extensive library of pre-made tools and workholding elements delivers high quality simulation.

Improving the Process

After the proper operation sequencing is done, all the turrets and moving axes can be easily synchronized. Operations can be switched around to optimize the process, ensuring that idle times are reduced to a strict minimum. The software offers a very clear view of how the program will run on the machine. The simulation can be viewed to the millisecond, providing unparalleled feedback on the machining process.

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